Technibel CAFM1V Series Technical Data Manual page 10

1. Model Selecting and Capacity Calculator
1-2. Procedure for Selecting Models and Calculating Capacity
I Model Selection Procedure
Select the model and calculate the capacity for each refrigerant system according to the procedure shown below.
Calculation of the indoor air-conditioning load
G
Calculate the maximum air-conditioning load for each room or zone.
Selection of an air conditioning system
G Select the ideal air conditioning system for air conditioning of each room or zone.
Design of the control system
G Design a suitable control system for the selected air conditioning system.
Preliminary selection of indoor and outdoor units
G Make preliminary selections that are within the allowable range for the system.
Check of the tubing length and elevation difference
G
Check that the length of refrigerant tubing and the elevation difference are within the allowable
ranges. ................................................................................................................ 2-4, 2-15 – 2-16
Calculation of the corrected outdoor unit capacity
G Capacity correction coefficient for outdoor temperature conditions ..........................2-4, 2-6 – 2-7
G
Capacity correction coefficient for tubing length and elevation difference ........................ 2-4, 2-8
G Heating capacity correction coefficient for frosting/defrosting ............................................2-4, 2-7
Calculation of the corrected capacity for each indoor unit
G Capacity correction coefficient for indoor temperature conditions ......................................2-4, 2-8
G
Capacity distribution ratio based on the tubing length and elevation difference....2-4, 2-15 – 2-16
Calculation of the actual capacity for each indoor unit
G Calculate the corrected indoor/outdoor capacity ratio, based on the corrected outdoor unit
capacity and the total corrected capacity of all indoor units in the same system. Use the result to
calculate the capacity correction coefficient for the indoor units. ....................................2-4 – 2-8
G Multiply the corrected capacity of each indoor unit by the capacity correction coefficient to calcu-
late the actual capacity for each indoor unit. ............................................................................ 2-6
Recheck of the actual capacity for each indoor unit
G If the capacity is inadequate, reexamine the unit combinations.
Example 1: Increasing the outdoor unit capacity ........................................................ 2-17 – 2-18
Example 2: Increasing the indoor unit capacity .......................................................... 2-17 – 2-18
Design of tubing
G Create a tubing design which minimizes the amount of additional refrigerant charge as much as
possible. ......................................................................................................................2-14 – 2-15
G If tubing extension is expected in the future, create the tubing design with adequate considera-
tion for this extension.
G Select the tubing size for the main tube (LA) up to the No. 1 distribution joint based on the rated
cooling capacity of the outdoor unit. Select tubing sizes after the distribution point based on the
total rated cooling capacity of the connected indoor units.
Calculation of additional refrigerant charge amount
G Calculate the additional refrigerant charge from the diameters and lengths of the refrigerant tub-
ing. Even if the gas tubing diameter was increased, determine the additional refrigerant charge
based only on the liquid tubing size. ...................................................................................... 2-21
G Check the minimum indoor capacity (limit density) with respect to the amount of refrigerant. If the
limit density is exceeded, be sure to install ventilation equipment or take other corrective steps. 2-22
Design of electrical wiring capacity
G Select a wiring capacity according to the method of power supply. ...................................... 2-32
Design of Mini Multiset
2 - 3
2
..................
2-2